Various security devices have been provided for windows to prevent intruders from entering the building through the windows. Most of these devices consist of a grill or a frame of bars fixedly connected to the window frame in which the window is mounted. Some security devices are detachably connected to the window frame to provide authorized access to the building through the window, or to facilitate cleaning the window.
While these window security devices have been generally satisfactory for their intended use, they have been subject to certain disadvantages. For instance, the mounting assembly for securing the security device to the window is usually accessible to the intruder so that it can be easily removed from the window, and when installed on a basement window, which is usually some distance above the basement floor, an emergency exit through the window after the security device has been removed requires the use of a ladder.